Paper-machine



2 sheets-sheet 1,

T. STEWART.

PAPER MACHINE.

( No Model.)

Patented Ma 13. 1884.

(No Model.) T. STEWART* 2 'sheets-sheen 2.

PAPER MACHINE. No. 298,634. Patented May 13, 11884.

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WITNESSBS N. PETERS. Phulo-Limugmpher. wnshingtun, D4 C.

7"safran STATES PaTnivT Ormes..

THOMAS STEVART, OF PHILADELPHIA, PENNSYLVANIA.

PAPER-MACHINE SPECIFICATION forming part of Letters Patent No. 298,634.1-, dated May 13, 1884. Application filed October 20, IES-3. (No model.)

To will who/it it may concern.-

Be it known that I, THOMAS STEWART, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Paper- Machines 5 and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying two sheets of drawings, which form a part of this specification, and in which- 1 y Figure l is a side elevation of my improved paper-machine, and Fig. 2 is a plan or top view of the same.

Similar letters of reference indicate corresponding parts in both the figures.

My invention has special reference to machines for manufacturing paper which is reenforced or strengthened by a textile fabric or by parallel threads embedded in the paper body. In the manufacture of this class of paper, in which the woven web or rc-enforcing fabric, whether this be in the :nature of a web or in the nature of a number of parallel threads not connected by a woof or weft, the difficulty has heretofore been to effect the proper adjustment ofthe speed of the dryingcylinders to the press-rolls and the web of reenforcing fabric; and the object of my invention is to overcome this difficulty, and to so construct the machine that the adjustment of the drying-cylinders relative to the speed of the pressrolls and of the web may be eii'ected with the utmost nicety and greatest possible degree of accuracy.

In the accompanying two sheets of drawings, D and Drcpresentthc drying-cylinders, and C C' the press-rolls.

In the manufacture of ordinary paper, the drying-cylinders are always speeded faster than the press-rolls-say from two to four per cent. faster, sometimes as low even as one per cent., or less, and sometimes again as high as from five to six per cent.; but they are invariably speeded faster than the press-rolls, and never slower. The reason for this is, that the paper, in passing from the second pressroll,'C,in itswet condition, sags down. from its @wn weight, as indicated by the broken line b, and if not' taken up by the increased speed of the drying-cylinders, it would soon drop vdown to the broken lineshown at m and drag on the scraper or doctor yt, and break the sheet. Hence the necessity of increased speed ofthe dryimg-cylinders in the manufacture of ordinary paper. But in the manufacture of my textile paper orpaper re-enforced by a web or threads inlaid in the body of the paper while in a pulpy state, as described in my Patent No. 265,884, dated October l0, 1882, this is changed, and the web has a fixed speed, the same as the forming-cylinder A, (or the endless wire-cloth ap ron on a Fourdrinier machina) which is the same as the speed of the pressrolls, or a little less speed, down to, say, two or three per cent. slower than the pressrolls and forming-cylinder or its equivalent. This becomes necessary for the reason that any increase of the speed of the drying-cyL inders, no matter how small, would soon so strain the web or the parallel threads as to break them.

My improvement consists in so constructing the machine that the speed of the dryingcylinders may be adjusted with the greatest precision, so as to correspond to the speed of the press-rolls and forming-cylinder, or else run a little slower than these; and it further consists in providing the machine with an adj ustable tension-frame and tension-rolls,which latter may be stationary or otherwise, for effecting the proper tension of the re-enforcing threads or web before this is embedded in the paper fabric. rlhis is for the purpose of stretching the fabric'at the tension-rolls sufficiently to causethe threads or webbing, by its elasticity, to contract to such a degree between the press-rolls C C and the guide-roll Tas to make up for the decreased speed of the drying-cyl nders when these are speeded at a slower rate than the press-rolls.

The adjustment ofthe speed of the dryingcylinders in the manner and for the purpose above set forth may be effected in various ways; but I prefer to use an expanding pulley, made to expand by a scroll in substantially the same way as the scroll on the ordinary universal chuck, and having forthis purpose two slots in the scroll-plate provided with adjustable stops S and S', so that the diameter of the pulley can be adjusted with the greatest IOO swer my purpose very well, and I desire it understood, therefore, that I do not limit or confine myself to any particular pulley or expanding pulley to accomplish the object aimed at.

If desired, the machine maybe constructed with compound pulleys, each pulley having a flat face and a cone-face, as shown at j and t', which are used in adjusting the drying-cylinders for the manufacture of textile paper, while the pulley-faces h. and g are used in the manufacture of ordinary paper, the belt 7c being adj usted for textile paper, as shown in the drawings in full line, and for ordinary paper, as shown in dotted lines.

In order, for the purpose hereinbefore set forth, `to adj ust the tension of the parallel threads or webbing, which is to be embedded in the'paper, and which is fed tothe machine from the roll marked It, I employ a tensionframe consisting of two rollers, (shown at a and b,) which are grooved spirally outward from the center, as shown in Fig. 2. These rollers arejournaled parallel to each other and at the proper distance apart between a pair of arms, p and p', which are hinged upon the vat in which the forming-cylinder A revolves, or upon any suitable part of the machine adjacent thereto, in such a manner that the position ofthe rolls may be shifted into the position indicated in dotted lines in Fig. 1. The spirally-grooved rollers a andhb are so arranged in their frame or arms p and p that they may be fixed or made stationary instead of revolving as the web passes over them, if desired, according to the tension which. it is desired to bring to bear upon the threads or webbing. The moving of the rollers up or down increases or decreases the tension when the rollers are lixed or stationary. Where parallel threads are used instead of a connected web', the tension-rollers should not be grooved butleft plain. A strap, d, is xed at one end in the stud o, and is passed around rollers a and b, as shown in the drawings, and provided with weights c at its free end. 'Ihe re-enforcing threads or webbing (shown at W) is passed around the rollers, as indicated in the drawings, on its way to the forming-cylinder, the spiral grooves in the rollers operating to take out creases or wrinkles in the webbing before it reaches the forming-cylinder. Vhere comparatively close-meshed webbing is used-say from six to twenty squares to the inch-it is desirable to fix the rollers in their frame so that the 'webbing will pass over them without revolving them, and in that case it is also desirable to shift the tension-frame into an intermediate position between the positions shown in full line and that indicated in dotted lines; but for more open webbing-say from 4two to six squares to the inch-the rollers should be allowed to move or revolve with the webbing, thus lessening the liability of displacing the weft or filling. The strap d, with its weights c, the gravity of which may be regulated at will, operates to give the necessary stretch or tension to the webbing against which the rollers bear.

Having thus described my invention, I claim and desire tosecure by Letters Patent of the United States- 1. The process of embedding are-enforcing fabric, whether a connected web or a number of parallel threads, in paper during the process of its manufacture, which consists in feeding the re-enforcing fabric to and embedding it in the paper while in a pulpy state, and then adjusting the speed of the drying-cylinders to the same speed as the press-rolls and forming-cylinder or its equivalent, or'slower, substantially as and for the purpose shown and set forth.

2. A machine for the manufacture of textile paper or paper re-enforced by ai web or separate threads embodied into the paper fabric while in a pulpy state, provided with an expansion-pulley or its equivalent, whereby the speed of the drying-cylinders may be adjusted to the same speed as the press-rolls and forming.- cylinder or its equivalent, or slower, substantially as and for the purpose shown and set forth.

3. In a machine for the manufacture of textile paper, or paper re-enforced by a web or separate threads embodied intol the paper while in a pulpy state, an adjustable tensionframe 'provided with tension-rolls and with weights for regulating the pressure or purchase of the rolls against the re-enfo'rcing fabric, whereby the stretch or tension of said fabric may be regulated in conformity to the speed of the drying-cylinders which take the fabric embodied into the paper from the press-rolls, substantially as and for the purpose shown and set forth.

In testimony that I claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.

THOMAS STEWART.

Witnesses:

DAVID C. DENNEY, R. M. GREINER.

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